SITOP UPS500 builds on double-layer capacitors as energy storage units and backs up the 24 Volts for longer than a minute.

The advantage of these totally maintenance-free capacitors over lead rechargeable batteries is a long lifetime at high temperatures. Even at temperatures of 50 °C they still have more than 80% of their capacity after eight years. This means that the energy storage unit does not have to be replaced.

Lead rechargeable batteries, however, must be replaced annually at an ambient temperature of 40 °C, which is not uncommon in the control cabinet. At 40 °C, the capacitors only fall in capacity by 10%. Because the double-layer capacitors do not emit any gas, the control cabinet does not have to be ventilated.

The considerably shorter charging times also ensure that buffering is available again quickly when power is restored.

The IP65 version SITOP UPS500P in long metal housing is ideally suited to distributed use.